Help me reconstruct a possible near miss

Hello Guys,

Today I was on a flight JU374 (Registration: YU-APH) from Belgrade to Zürich. At aprox 19.48 - 19.49 (German Time) a decent size plane came very very close. The plane seemed to be like 100meters away from us on the left side going up kind of crossing our path. It looked quite freaky.
Now im wondering how close it came. On flightradar24 I can check the history but it only shows the JU374. Is it possible to check what other airplane was that close to it at that time.

Can anyone help?