Question: Extracting a specific operand from an expression

Hi, I am looking for a way to extract a specific operand from a given expression. Something similar to the coeff command, but rather than just the coefficient, I want the whole term. For example,
Given an expression A:=u[1,2]+u[2]*u[1,1,1], if I want to extract the term u[2]*u[1,1,1]. then a command, let's say LT which takes the expression and a component, which then will return the term containing that component.
input: LT(A, u[1,1,1])
output: u[2]*u[1,1,1]


Thank you for your help.

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