Obviously made of cast brass, originally had a gold wash or plated. I'm thinking furniture decoration or possibly an escutcheon plate.
Your find looks like an exaggerated version of a quatrefoil design, likely dating to the early 20c.
"The quatrefoil has been used in global art and architecture for centuries, and designers and artists still use it today. No one knows for sure where it came from, although some sources connect it to ancient Islamic art and trade between cultures along the Silk Road. It's also possible that the shape developed independently in more than one location. Regardless of its murky origins, the quatrefoil was popular throughout Europe. It appeared in medieval heraldry and was sometimes regarded as a symbol of good luck."
I have seen gilt metal small quatrefoil frames for holding small photos or mirrors. However the size and shape of the quatrefoil in relation to the total plaque seems not ideal for that.