RELATEDTABLE Evaluates a table expression in a context modified by the given filters.
Syntax
RELATEDTABLE(tableName)
Parameters
TableName – The name of an existing table using standard DAX syntax. It cannot be an expression.
Return Value
A table of values. The RELATEDTETABLE function changes the context in which the data is filtered, and evaluates the expression in the new context that you specify.
Reference Data
https://docs.microsoft.com/en-us/dax/dax-function-reference