Check in the Brose by: pulldown at the top of the tree view
If Artist (overview) is one of your choices (a preset in OCD terms) then that's it
If Artist (overview) has disappeared - I think it is one of the standard settings, do this:
1. Select Artist in the Browse by:
2. Right click in the tree view
3. Select Customise view
4. The right panel should have just Artist as an entry
5. Highlight that
6. Check Overview below the right panel
7. Save as preset
8. You can give it whatever name you want
If you do not want artist to include tracks on compilation disks also Check No tracks below the right panel before saving as a preset