Total Commander

Option, when applying a Filter:
[x] Apply to all Tabs in this Pane. (A remembered Setting)

If Custom Columns were able to Filter, this would solve most issues I believe. Currently we can have a different Custom Column applied to every Tab. A filter applied to a Custom Column would override the normal global per panel filter.

Custom Column information could also be viewed and changed from the Tab context menu, instead of soley from the tabStop context menu.
This would alleviate Lefteous' concern about knowing what filter is in place before activating a tab.

Well, in MS Excel and a bunch of other apps a filtered column header shows a telltale funnel symbol to indicate filter is active.
Just as a locked tab has an asterisk added to it to indicate its locked state, it would be very easy to indicate filtered state of a tab by adding a funnel symbol (there must be some suitable symbol in most fonts for that) or some arbitrary symbol, say "#", to show the tab is filtered.

Total Commander 10.00 public beta 8

history.txt wrote:25.04.21 Added: Configure option to save displayed file types (e.g. *.txt) separately for each tab: Configuration - Options - Folder Tabs - Save displayed file types separately for each tab (32/64)

And the filter can as always be seen in the "Current directory" bar just above the tabstop header.