Hello everybody sorry tried to find examples but didnt find.
i need a filter to rename the title with the inside of the brackets and without the brackets.
before: all (all2)
after: all2
hope its understandable 
Not yet...
A Filter reduces the amount of listed files according to your filter content.
If you want to rename your TITLE, you need a Convert Tag -> Tag or an Action.
Do you want to to replace the current content in TITLE with everything between the first round opening bracket ( and the last round closing bracket ) ?
yes in the brackets should give the title.
of course filter is wrong
%title% HAS "(" AND %title% HAS ")"
Modify title:
Convert>Tag-Tag for TITLE
Format string: $regexp(%title%,'.*\((.*)\)',$1)
Menu Convert and Tag -> Tag.
This way you see what this would produce immediately, before you execute the Format string.
As an Action it would be "Replace with regular expression"
As Format string I would suggest:
$regexp(%TITLE%,.?\((.*)\),$2)
To get everything between the first occuring bracket and last occuring bracket.
You mix different steps.
The Filter only reduces the list of possible candidates in all your loaded tracks.
For the reduced/filtered tracks you apply the Action.
The regular expression itself is the part
'.*\((.*)\)'
or
.?\((.*)\)
@ohrenkino's syntax
$regexp(%title%,'.*\((.*)\)',$1)
is - as written - for Convert Tag -> Tag
okay tagg tag with this
$regexp(%title%,'.*\((.*)\)',$1)
is working
how do i get this to action ?
Please read this answer again.
with that it gives back the outside of brackets
Could you please show us what you entered in which action editor?
Or: please copy the offered expressions thoroughly. Right now I have the impression that you left out a couple of vital characters.
Your "Treffer ersetzen durch": $2
My suggestion: $1.
Also, I am pretty sure that it should be
"Regulärer Ausdruck: .*?\((.*)\)
Just a hint: to debug regular expressions it is much easier to test them in Convert>Tag-Tag and then copy the working format string to the corresponding action "Replace with regular expression" and distribute the 3 parts of the regular expression scripting command into the 3 objects of the action dialogue.
That way you avoid to leave out characters or create an all new regular expression.
You can use Convert Tag -> Tag with
Field:
TITLE
Format string:
$replace($regexp(%TITLE%,'(.*?)\s\((.+)\)',$2),'(',,')',)
This would take the content between the first
( bracket and the last ) bracket and remove all the brackets between.
You get from
Evening News (Goin' In) (Feat. Quelle Chris)
to
Goin' In Feat. Quelle Chris
And from
Tools Of The Game (Interlude) (ft Wallo) (prod Teeko)
to
Interlude ft Wallo prod Teeko
If you insist to create an Action (without any preview) than you have to create two Actions in a Action Group.
