You can hide/show section numbers above staves in divisi sections in each layout independently; for example, to clarify which staves correspond to sections in the divisi when divisi changes occur partway through systems, or to show a change in weighting between staves.
Procedure
Press Ctrl/Cmd-Shift-L to open Layout Options.
In the Layouts list, select the layouts in which you want to hide/show divisi change labels above staves.
By default, the layout currently open in the music area is selected when you open the dialog. You can select other layouts by using the selection options in the action bar, clicking and dragging across multiple layouts, Shift-clicking adjacent layouts, and Ctrl/Cmd-clicking individual layouts.
In the category list, click Staves and Systems.
In the Staff Labels section, activate/deactivate Show divisi change labels above staves.
Click Apply, then Close.
Result
Section numbers are shown above staves in the division when Show divisi change labels above staves is activated, and hidden when it is deactivated.
Note
This does not affect whether divisi section numbers are shown in staff labels before the initial barline on each system.