QGIS, labels offset for a line layer

I am working with rule based labels on a line layer and need to move the labels along different axes along the line. I want to move the label 2 along the line a few millimeters.

For the label 2, the placement is a curve, and the position is above the line. The labels 1 and 2 will repeat after 15 millimeters, and I need the label 2 to be offset from the label 1 along the line by a few millimeters. There is a distance parameter, but it is responsible for the offset not along the line, but across.

Сurrent setting for the first label

Current setting for the second label