I remember a few versions ago where you could for example make a folder named "1.12.2" and put mods in there. Then launching 1.11.2 for example wouldn't use those mods. Is there a way to do that now?
With older versions you can do this inside the mods-folder
for 1.12.2 mods
for 1.11.2 mods
and so on
You also can use own game-directories
In your .minecraft-folder create a new folder like "instances"
Inside create folders like "mod-1.12.2" or just "1.12.2"
Install Forge as usually (without using any new directories)
Go to "Installations" - New
Choose your Forge Version - at game directory navigate to the new folder
After running that profile, there you will find the own config-, mods- and other folders