Can be done rather early in the game. (probably somewhere during chapter 2)
When your character is roughly at level 11, open the menu -> Battle Options -> Support Skills.
Here you will find a list for all characters in the game. Once all of them show at least "SP 10", you can get the achievement. If not, play more story missions to quickly level up all support characters.
Select the first character on the list and try to look for two skills that require 5 SP each and activate them. If you can't find two 5 SP skills on that character, just select one 5 SP or 10 SP skill.
Then repeat the step above for all the other characters.
There are 43 characters in the game, so you only need to find 7 characters where you can select more than one skill. (There are more than enough, so don't worry).
For the achievement to unlock you need to close the menu.