filtering a list based clock time

[DPD16]

Yes the time is a critical component and is used as a basis for further analysis. the data is collected from a data logger. I had a formula (that I lost hence the request) that I could select the data set then apply a filter as I recall on a helper column to filter out "not equal to" but I don't remember how to write the helper form to separate the minutes

thank you for your response