You could just select spells "up to level XX". You know the level cap for a given expac, so that pretty well takes care of it.
The only exception is, when more than one expac has the same level cap, you may see some spells at the top levels which you don't have available yet. However, the spells list DOES show which expac the spell belongs to, so you'll have an indicator right there for which ones to ignore.
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Tatanka Wolfdancer, 115 Wood Elf Druid, 9 x 300+ Master Artisan, 7 maxed trophies (dang research! :)
Michone, 115 Troll Shadowknight
Anaceup Mysleeves, 115 Erudite Mage, 2 x 300 Master Artisan
Snookims Whinslow, 112 Erudite Enchanter, 2 x 300 Master Artisan
<Inisfree>, Tunare (Seventh Hammer!)