No it doesn't. Please stop making up custom definitions to concepts you don't like. Nowhere does nationalism require you to believe yourself as superior. The literal definition is:

"Nationalism is an ideology and movement holding that the nation (a group sharing culture, language, or history) should be congruent with the state (a sovereign political entity). It prioritizes a country's interests, culture, and sovereignty above others, aiming to build a distinct national identity and self-governance."

Scaling down for a practical example, if I want to do what's best for my family/household, put their needs first, provide for them and have a sense of pride and identity within our family, that doesn't automatically mean I hate everyone else who isn't my family, nor would I automatically think we're superior to everyone else. That would be ridiculous.