To give you a more detailled answer it would require to know more about the surrounding parts.
So I can give you only very general advice:
Create an action of the type "Replace with regular expression".
the wildcard for a universal string is ".*"
To separate and possibly reuse parts of the string, use "(" and ")".
To address reusable parts of a string, use $1, $2 etc.
So an expression for string with some text in front, inside and behind the brackets might look like this:
(.)([.])(.*)
To leave out the part in [ and ] enter (which would be string part $2)
Action: Replace with regular expression:
Field: _ALL
Regualar Expression: " *[.+?]" (without quotationmarks, just to show the leading space)
Replace matches with: "" (without quotationmarks, just nothing)
This solution will leave you a single space if the brackets occur at the begin of a line/field.For this case, se a second action:
Action: Replace with regular expression:
Field: _ALL
Regualar Expression: (^ | $)
Replace matches with: "" (without quotationmarks, just nothing)
Alternative solution:
Action: Format Value
Field: _TITLE
Formatstring: $trim($regexp(%title%,' *[.+?] *', ))
This solution works only for one tag field (TILE in th example), not with all fields in one go.