。
I can see an old woman in the shade of the tree.
Literal
Tree-shade [in-に] grandmother [subject-が] is [nominalizer-の] [subject-が] is-visible.
Two が-marked subjects in a row, which feels unusual but is grammatically clean: the inner clause おばあさんがいる ('there is an old woman') is nominalized by の ('the fact of an old woman being there'), and that whole nominalized clause is the subject of 見える ('is visible'). 見えるのが見える / can see [the fact that …] is one of the standard frames for 'I can see (someone) X-ing.'