Yup. If the tartan comes in double width (56 inches or wider generally) virtually every kiltmaker around will order 4 yds then split it into halves, rotate the upper half to line up with the lower then sew the two pieces together before building the 8 yd kilt, and hide the joint seam in one of the pleats. SOP.

Doesn't work for the occasional asymmetric tartan like the Maple Leaf, in which case you have to have 8 running yards of material of either single or double width to make one kilt. If you have 8 yds of asymmetric tartan and make one 8 yd kilt there will be an 8 yd remnant that has the tartan inverted in direction compared to the first kilt made from the other half.

If the fabric only comes as single width then you need 8 running yards, give or take, and there should be no seam to hide.

Same holds true for 4 yd kilts---i.e., you can make a 4 yd kilt out of 2 yds of double width material by splitting it, joining it, and hiding the seam in the pleats.