Does it matter from which source book you drag your level when you level up?

[Maetco]

The same class appears multiple times in the class list. Does it matter which you drag to the character sheet? In practice, do you need to drag the option from the book which has the right subclass?

[Zacchaeus]

Not specifically - no; When you drag in the level that gives you the archetype then you will get a choice of all the archetypes that you have in any open modules.

I generally drag from the PHB at all times (unless it's the artificer which isn't in the PHB).

[Griogre]

The implication of dragging from different books is that you will need that same book open that a player dragged from for a character for the rest of the campaign though. Thus as a DM since I don't want to have to have the SRD open all campaign, I close the SRD and just keep the PH open.

[grimmlock]

Because getting players to listen and herding cats are basically the same thing, and since they have to have the module with the archetype open, I just tell my players they have to use the book contains their archetype. That forces them to have the appropriate module open, and makes sure their won't be any missing abilities.