Install and activate in the Extension Manager. The extension “Template selector” (rlmp_tmplselector) is required!

Enter the required information in the Extension manager interface and set some lines of PAGE TS in the top level page (see Configuration section).

The extension extends “Template selector” through the XCLASS mechanism to fix a bug of this extension.

Every page becomes an own setting for the columns and one that affects the dropdown “Column” for all content elements on this page (so there are only those columns listed which are really available on the page).

Use the new click menu entry to initialize all pages of a branch with the new settings (see screenshot below). This is only available for “Admin” users (makes sense, doesn't it?). This is only necessary once, because the settings are always set on any change to the page record as long as the extension remains active!

Or use the Web/Info module in the “Pagetree overview” mode, activate all Levels, “Basic settings” and click for example on the edit icon next to “Alias”, this will open a screen to edit all “Alias” values of all pages of the selected tree part, but we don't want to change any “Alias” values here, simply click on the “Save and close” button to set the template to column mapping on these pages (remember: this is always set when you save the page record automatically). Done.