This is a pictograph of the peak of a mountain combined with a pictograph of a track. Hence, the symbol means summit path or summit route.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-1664 a: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 6: New material, untraced objects, and collections
outside India and Pakistan: Suomalainen Tiedeakatemia.