This is the dream interpretation of chimney sweep, or people climbing out of chimneys. The chimney sweep is a cleaner who specializes in cleaning chimneys. These workers used to be physically small in size, to be able to crawl along the narrow space of the chimney. As cleaning equipment got better, grown-ups or physically bigger people, could use brooms with long stick holders, to clean the narrow tubes of chimneys.
Why do we see chimney sweeps in dreams? Why do we need clean chimneys? Smoke that rises from a chimney denotes dirt, metaphorical dirt like gossip and other bad products from human machinations. Thus, when you see people climbing out of chimneys, it might mean the subjects of gossip are climbing out of the hidden crevice. Dirty laundry is going to be aired with exposure of secrets (and maybe skeletons in the closet).
On a simpler note, if you have a house that uses a chimney, then this dream might be a hint to get your chimney cleaned.