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An element that displays multiple records in an interface can have a fixed filter for the data and a connected filter element. While the fixed filter can have multiple conditions, and the connected filter element can have multiple conditions, you can have only one fixed filter and only one connected filter element.
The fixed filter has conditions set by the creator of the interface page. You can have or conditions here. However, none of this can be changed by the user. Any records that do not meet these conditions will not be shown to the user.
The connected filter element can be changed by the user. However, it cannot be set to show more records than are shown by the fixed filter. The connected filters are always combined with the fixed filter using “and”.
One option is to use a formula field that combines the fixed filter conditions. Then don’t use a fixed filter at all. Have the filter element filter based on the formula field. It’s an ugly workaround and can be hard for users to understand, but can work in a pinch.