Sentence examples for my domain from inspiring English sources

"my domain" is a correct and usable phrase in written English.
It is often used to refer to something that is under one's control or within one's expertise or responsibility. Example: "As the CEO of the company, sales strategies fall within my domain." This means that the CEO is responsible for and has control over the company's sales strategies. Another example: "I am the queen of this household, so decorating and home organization are my domains." Here, the person is stating that they have control over and are responsible for decorating and home organization in their household.