You can actively train your mind to be more expansive by following these practices suggested by Indeed and Vision Times : Broad-minded - Definition, Meaning & Synonyms

According to psychological and social perspectives from Verywell Mind and Quora , broad-minded individuals typically exhibit: A genuine interest in how other people think.

The ability to understand and share the feelings of others, even when they disagree.

Respecting the rights of others to express beliefs that may seem strange or radical.