yes
D minor
The subdominant in a scale is the 4th, which in the key of B-flat major is E-flat.
The dominant is the 5th, which in the key of A-flat major is E-flat. Then an E-flat major triad contains the notes E-flat, G, and B-flat.
The secondary dominant of b minor is a C# major chord.
A flat lowers the note by a semitone. As a key signature, a single flat indicates the key of F, meaning your B should be flat. Two flats are E and B, meaning the key is therefore B flat. B, E and A flat indicate the key of E flat ... and so on.
A flat lowers the note by a semitone. As a key signature, a single flat indicates the key of F, meaning your B should be flat. Two flats are E and B, meaning the key is therefore B flat. B, E and A flat indicate the key of E flat ... and so on.
The key signature that has B flat, A flat, E flat and D flat is Concert A flat Major.
There are two flats in the key of B flat major: B flat and E flat.
The dominant note is the 5th note in the scale. In the B Major scale, F is the dominant note.
Eb
B-flat and E-flat are found in B-flat major and G minor.
The key of B flat on the piano has two flats (Bb and Eb).
Assuming the key signature has only one flat (B Flat) then the key is either F Major, or D minor.