Problem
I stumbled about this topic when I tried to convert all appearances of ![[imageXYZ.png]]
to :
Crtl+Shift+F to open search
Type
!\[\[(.*)\]\]
into the search fieldActivate the Regex button (.*)
Type

into the replace field
Explanation
$1
references the Regex match from the search field. For infos regarding Regex, visit regex101.com.