Filter Inner Sections
Step 1:
Click on the pencil icon to access the Button Settings (on the button, that you want to filter with). You can also use images, or any other element to trigger the filtering. It doesn’t have to be a button module.

Step 2:
Go to Advanced → CSS Class. Here you add the
ef-button
class.
Step 3:
Additionally, add any category that you want to filter with that button like that: efc-[your category] e.g.
efc-cats
.
Buttons have to be in a separate section, than your filterable elements. Or you add the df-buttons class to your button row (Premium features).
Step 1:
Click on blue icon to access the Section Settings.

Step 2:
Go to Advanced → CSS Class. Here you add the ef-area and the ef-inner-sections class.
Step 1:
Click on the edit inner sections icon to access the settings.
Step 2:
Go to Advanced → CSS Class.
Here you add all the efc-[your category] class you want, e.g. your efc-cats class.
Step 3:
Do that for all inner sections you want to make filterable.