Sort your box by recent put in this string in (copy from comments) and mega evolve from top to bottom skip whenever it coasts to much energy (can't filter for that yet)
proto-,meg,mega1-2&proto-,mega-,megaevolution
The megaevolved pokemon will serve you as a bookmark, so you can do a few and know where you left of later
Substitute "megaevolution" with the correct string for your language with this
Every Pokemon that reaches Mega level 3 will automatically not show up unless megaevolved and every Pokemon with insufficient energy also won't show
Comment if any problems arise or if you got suggestions to improve it
by Taizai_Kouman