It looks like Collie mullens.

Maybe not hibiscus I’m not familiar with plants in your area

Hibiscus syriacus 'Collie Mullens' it seems. Rose of Sharon.

Definitely H. syriacus - whatever the particular cultivar.

And therefore a shrub rather than a tree.

But conducive to growing in the multi-trunk tree form.

And although you saw it in a shady spot they do far better in the sun. The one in your photo is rather threadbare compared with a happier specimen.

The many tall tree-like ones I have seen here have all been leaning markedly or have had other things about their appearance/condition that did not make them come across as fully committed, bona fide trees.

I like this species much better hard pruned in spring to remain short and bushy. And without the flowers concentrated mostly in the upper sections of long, straight stems that branch comparatively infrequently.