。
I left the present for her at home.
Literal
Her [toward-へ] [possessive-の] present [object-を] home [at-に] left-came.
へ marks the direction/recipient of the present, and の nominalizes the preceding phrase into a modifier for プレゼント. 置いてきた uses the compound auxiliary ~てくる — here meaning 'did (at another place) and came (to the current location),' i.e., left the present behind at home. The subject ('I') is omitted.