dwarf red buckeye does well in the situation you described. They bloom in spring by the time they are only 3 to 4 ft. tall and are a source of nectar for spring migrating hummingbirds when little else is in bloom.

Penny

Stewartia, Dogwood, redbud, halesia. Stewartia are especially nice.

Understory trees that I grow in my yard:
Flowering Dogwood, Pagoda Dogwood, Kousa Dogwood, Redbud, Fringetree, Paw Paw, Ashii Magnolia, Magnolia tripetela, Red Buckeye.
All are growing well and are fully hardy here in Hamburg, NY.