Here are eight examples of sentences where prepositional phrases function as object complements:

She considers the project in its final stages.
We found the book on the shelf.
They named the team after their hometown.
The committee elected him as their spokesperson.
I always want my coffee with a dash of cinnamon.
The teacher left the students in a state of confusion.
The artist painted the wall with vivid colors.
The coach deemed the players ineligible for the tournament.

In each example, the prepositional phrase provides additional information about the object, further specifying or completing its meaning.