In order to unlock this achievement you need to recruit all 6 companions.
This trophy can be missible as you might choose not to take companions with you, so make sure to always agree to recruit them.Video with all the Companion locations:
► Timestamps:
[0:00] Parvati
[1:31] Vicar Max
[3:23] SAM
[6:20] Ellie
[9:42] Felix
[10:35] Nyoka