Hilchos Maasei Hakarbanos 9:6

The three types of peace offering are brought as follows: The animals are slaughtered and their blood sprinkled, as has already been discussed. They are skinned and the parts to be offered are removed. The meat is then cut up, the breast and the right thigh being put aside. The parts to be offered are put with the breast and thigh on the hands of the owners (i.e., the ones bringing the offerings). A kohein puts his hands under those of the owner and leads him in waving these things “before God,” i.e., in the east. Whenever waving must be performed, it occurs in the east.

Hilchos Maasei Hakarbanos 9:7

Waving is performed as follows: The parts are waved back and forth, up and down. For a thanksgiving offering, one bread is taken from every ten brought with it and placed with the breast, thigh and parts to be burned. All of these things are waved on the owner’s hands in the manner described.