I want to separate two words with Space after comma

Case: S.P. Balu,Chitra
In the above case I want to separate those two artists with Space like below
S.P. Balu, Chitra

is there any option to do that?

There is an action for that, a simple "Replace".
Search string would be: ,
(read "comma")
Replace string: ,
(read "comma blank")

If you accicdentally create double blanks then use another "Replace" action where you replace 2 blanks with 1.
If you have questions about these actions, see /t/967/1 first.

This answer enough for me. But I am expecting some more...
can we avoid double blanks problem?

You could devise a filter so that you see only the files that have no blank behind the comma:

%field% HAS "," AND NOT %field% HAS ", "

Wow...

     that's working fine.  <b>Thank you</b>

and

can I avoid/add more than one word in filter?

Ex: %artist% HAS "Balu" AND NOT %artist% HAS "S.P. Balu"

in this case I able to avoid only "S.P. Balu". But I want to avoid "SP Balu" also.
ie. I want to avoid more than one word.

If you really want to look for a specific string and that only, then use "IS" as filter instruction:
%artist% IS "Balu"
As "Balu" is part of the string that you are looking for and also part of the string that defines the exclusion criteria, it will not lead to a valid set. You would have to look for a different condition e.g.
%artist% HAS "Balu" AND "$len(%artist%)" GREATER 4

Ok... ohrenkino now I want to more clear about my concern.

Balu
SP Balu
S.P Balu
SP Balusubramanyam
S.P. Balasubramanyam

these all words refletcs only one artist "S.P. Balu"!
So I want to replace with "S.P. Balu" where ever comes above all words.

Now I am using "Replace" action, replacing one name once at a time.
Is there any easy way to solve this?

Set Filter: ARTIST HAS " Balu" OR ARTIST HAS " Bala"
... or ...
Set Filter: ARTIST MATCHES "S.?P.? Bal.*"

Check displayed files.
Remove possible false positives from the file list.

Use action (quick) "Format tag-field"
Field: ARTIST
Formatstring: 'S.P. Balu'

Ready.

DD.20140803.1441.CEST

It might be even quicker to simply enter the correct Name in the tag panel and then save the modification ... I do not see the necessity for a one-off to create an action.

And in general: if I want to get all occurances of a name fragment then the whole hustle of different spellings is superfluous anyway as it won't do much harm to overwrite already correct files with correct data again...
Could it be that I do not understand the complexity of this problem as I do not see any?

Note: I have suggested action (quick) ...
... but using [Ctrl+Q] Tag-Panel ...
... and entering the new string into the artist edit box might be the easiest way.

DD.20140803.1529.CEST

Hi DetlevD

Your suggest filters

ARTIST HAS " Balu" OR ARTIST HAS " Bala"
... or ...
ARTIST MATCHES "S.?P.? Bal.*"

are working very good.

But problem is in ARTIST field not only filled with single artist. Multiple artists are there.
When I am using your suggested 3rd step (even as per ohrenkino TAG PANEL method) it's replacing all artists with single artist 'S.P. Balu'.
Ex. SP Balasubranaiam, Chitra, S. Janaki
After the process: S.P. Balu

So this method not working properly.
................

I think if we can use the above filters in Actions (Quick) list like "Format value, Replace with regular expression...." or any other is workable! Is it possible?

Yes, and this is a completely different problem from what you told us in the former posts. Even in post #7, where you wanted to be clearer, you left out the bit that you want to keep the rest of the field.

You will have to cater for several source strings as an "SP Balusubramanyam" is something completely different from "S.P. Balasubramanyam". And even the "Balu" (1st string) vs. "Bala" (2nd string, see your post in #7) will make it more or less impossible to think of a pattern that will lead to a sensible result.

You could try a "Replace with Regular Expression" with a
Search string: (S.* Bal., )(.)
Replace with: S.P. Balu $2

But as I cannot tell if there are other artists that may match the criteria.
In the meantime you probably could have replaced the artists manually.

A different problem needs a different strategy.
Use the strategy 'divide and conquer'.

http://en.wikipedia.org/wiki/Divide_and_conquer
http://en.wikipedia.org/wiki/Divide_and_conquer_algorithms

In relation to Mp3tag this could mean to apply the Filter.
This could mean to count the amount of commas in the tagfield ARTIST.
You should be imaginative.

DD.20140806.0846.CEST

$regexp(%ARTIST%,'^(.*)(\bS\.?\s?P\.?\s?Bal.*?\b)(.*)$','$1S.P. Balu$3') "aaa, bbb, S.P. Balasubramanyam, ccc, ddd" -> "aaa, bbb, S.P. Balu, ccc, ddd" "aaa, bbb, S. P. Balasubramanyam, ccc, ddd" -> "aaa, bbb, S.P. Balu, ccc, ddd" "S.P. Balasubramanyam" -> "S.P. Balu"

DD.20140806.0932.CEST

Hi ohrenkino,
the method you told...

You could try a "Replace with Regular Expression" with a
Search string: (S.* Bal., )(.)
Replace with: S.P. Balu $2

not worked! When I am using this... nothing happening!!

Hi DetlevD

I really don't know how to use the code which one you showed in the lost post. Please clarify me how to use it. I am really very eager to understand this new method.

You can check your regular expression with the function convert>tag-tag
Enter the field, then enter as format string:
$regexp(%artist%,'(S.* Bal., )(.)','S.P. Balu, $2')

This should lead to
S.P. Balu, S. Janaki

so ... that nothing happens indicates that you have not told us the whole truth about the contents about the fields.