kalanı hak ettigi gibi ağırladıysa bu yürek, gideni de layık oldugu gibi uğurlamasını bilir elbet..

       " This heart certainly knows how to say goodbye to the one who leaves, just as it(this heart) respectly treated the one who stayed as he/she deserved."

My attempt which has a similar meaning -

This heart, if it treated the one who stays respectfully, like they deserved, also surely knows how to bid farewell to the one who goes, like they deserve.

Thank you so much! I like how you coloured it so that I know what each word exactly means

However can you please explain what the writer is saying?

I guess it could mean something like, if someone treated  you well while you stayed with them, then they would also treat you like you deserve when you leave them. It depends on how the relationship was when you go. So rather than say they would treat you well, it becomes the ambiguous ´like you deserve´, which could be good or bad.

These statements are always able to be interpreted in many ways, depending on your own situation.