Buttons and buttonholes were simple fastenings holding two different pieces of material together. Spiritually this can represent uniting the physical and spiritual realms into one coherent whole.
Psychological / emotional perspective: Buttons were originally a form of insignia, allowing easy identification of friend or foe.
If our attention is drawn to buttons in a dream, it is usually to bring about such recognition.
Material aspects: The size, shape and configuration of the button and buttonholes may be important.
An ornate button will have a different relevance to a simple one; more work or effort is required for the former.
A particularly decorative buttonhole suggests that more energy needs to be put into ‘fastening down’ a project – it perhaps needs to be more upfront.