[Dynamic_Reality]

So it came up on a game recently and was wondering, of a player was defending against an attack and used 2 Minor Actions, could they add both their Athletics and Close Combat as a combination of Dodging and Blocking?

[Xenon]

Rules doesn't say, but it kinda make sense that you either attempt to block an attack or you attempt to dodge it.
If you decide that PCs can do both against one single attack then also NPCs should have that as an option.

(also note that block is only available against melee attacks)

You can also combine Full Defense (which last the entire combat turn) with Dodge (and/or Block).

[MercilessMing]

There are lots of ways to add dice to Defense Tests, so I personally wouldn't recommend allowing characters to use both Dodge and Block on the same test.  The combat meta in 6e can already become lopsided in favor of defense, which isn't great because it makes the game drag.