Pathfinder Ultimate Psionics multiclassing

[ABruce1974]

Would it be possible to multiclass a character in two Psion disciplines? Example: Psion (Egoist)/ Psion (Nomad)

[Psyren]

No - however the Dual Disciple archetype (https://www.d20pfsrd.com/alternative-rule-systems/psionics-unleashed/classes/psion/archetypes/dreamscarred-press/dual-disciple/) does let you choose both disciplines (and thus learn their discipline powers at the appropriate times) in exchange for a small ML penalty to any powers they manifest outside those two disciplines.

Alternatively, if it's just the discipline-only powers you're after, you can pick those up without specializing in that discipline - whether through Expanded Knowledge, or having another psion impart them to you using Psychic Chirurgery.