how to find duplicates

[#1]

Hi Experts,

i have a document which has Passenger ID, Journey ID, Direction,  respective calendar for year, month.

Each Passenger will have unique passenger ID & each journey will have unique Journey ID and direction will be either inward or outward.

One passenger may have multiple journeys on the same day but they will be either inward or outward.

A passenger cannot have multiple journeys on a same day for inward alone (or outward alone). this is called duplicate entry.

i need to report the duplicate entries in a table(chart).

how can i bring duplicate passenger ids alone in a chart.

Please help me to find solution.

[#2]

Thanks to all