Using Semiconductor sample data as example.
Starting graph:
jthi_0-1635573987800.png
two different ways come to my mind, drag and drop NPN2 and NPN1 to area in front of NPN4:
jthi_1-1635574071002.png
jthi_2-1635574083158.png
after both have been moved:
jthi_3-1635574098632.png
Other option. Remove all variables from Y-axis, select all variables of interest from the column list:
jthi_4-1635574140300.png
and drag and drop them at the same time to Y-axis:
jthi_5-1635574178255.png
-Jarmo