The Gimp 3.0 layers selection has its pluses and minuses 
(thinking of the distribute tool as a minus)
However, In the layer dock, ctrl-click to select and add individual layers. Shift-click to select a block. Much the same as other programs.
The layers are highlighted, maybe not easy to see if using that awful black theme.
The number of selected layers shows top of the layer dock.
There is a border indicator for the extents of the selected layers.
Menu items that are not applicable are greyed-out.
(thinking of the distribute tool as a minus)However, In the layer dock, ctrl-click to select and add individual layers. Shift-click to select a block. Much the same as other programs.
The layers are highlighted, maybe not easy to see if using that awful black theme.
The number of selected layers shows top of the layer dock.
There is a border indicator for the extents of the selected layers.
Menu items that are not applicable are greyed-out.