HI
how do i add in mameUI32 0.145' another folder like bosses or manuals in tab control ? i know the default is:snap,flyer, cabinet,marquee,etc.
You can't just "add" additional folder tabs from the UI.
The tab options displayed, are 'hard coded' in the mameUI32 0.145 source code. (An alternative is to change the source code, to add the "Bosses", "Manuals", etc, you desire, and then recompile the version of Mame.)
Hope this answers your question!

- John