UNDO "Make this the only selectable layer"

[Nabaz_Gharib]

this question was asked 4 years ago, but still no solution. 
Solved: UNDO "Make this the only selectable layer" - Esri Community

apparently, it should be simple and straightforward, but practically it is a pain.

I have 4 CAD layers in a map, and I made one of them as only selectable, the problem is the CAD files are groups within groups. now when I want to make all layer selectable I have to go to all groups expand them and make all of the selectable. 

this procedure is fine for on time, but for several time it is simply a pain. I looked at arcpy to find away iterate over layer to make all of them selectable but could not  find  a solution.

i hope make this would be added as feature to arcpro or some post a solution here.

[MitchHolley1]

If you go to Contents pane in the 'Selection' tab, you can select all the layers you want to turn on, then hold CTRL + SPACE bar. That should select/unselect the layers.