If I'm reading your question correctly, it sounds like you have a single column of data that has both your X values and Y values in it.
Do you have a column that identifies whether a row is an X or Y value? Do you have another column (or combination of columns) that identifies which XY pair that row belongs to?
For example, in the table below Value has both X and Y values. Measure identifies whether a row is a height or weight value, and name, age, sex together identify a unique entity for that height or weight.
If this is the kind of data you have then yes, Tables->Split is exactly what you need.
You would complete the Split dialog with Measure in the Split By role, Value in the Split Columns role, and name, age, sex in the Group role.
name
|
age
|
sex
|
Measure
|
Value
|
KATIE
|
12
|
F
|
height
|
59
|
KATIE
|
12
|
F
|
weight
|
95
|
LOUISE
|
12
|
F
|
height
|
61
|
LOUISE
|
12
|
F
|
weight
|
123
|
JANE
|
12
|
F
|
height
|
55
|
JANE
|
12
|
F
|
weight
|
74
|
JACLYN
|
12
|
F
|
height
|
66
|
JACLYN
|
12
|
F
|
weight
|
145
|
LILLIE
|
12
|
F
|
height
|
52
|
LILLIE
|
12
|
F
|
weight
|
64
|
TIM
|
12
|
M
|
height
|
60
|
TIM
|
12
|
M
|
weight
|
84
|
JAMES
|
12
|
M
|
height
|
61
|
JAMES
|
12
|
M
|
weight
|
128
|
ROBERT
|
12
|
M
|
height
|
51
|
ROBERT
|
12
|
M
|
weight
|
79
|
BARBARA
|
13
|
F
|
height
|
60
|
BARBARA
|
13
|
F
|
weight
|
112
|
ALICE
|
13
|
F
|
height
|
61
|
ALICE
|
13
|
F
|
weight
|
107
|
SUSAN
|
13
|
F
|
height
|
56
|
SUSAN
|
13
|
F
|
weight
|
67
|
JOHN
|
13
|
M
|
height
|
65
|
JOHN
|
13
|
M
|
weight
|
98
|
JOE
|
13
|
M
|
height
|
63
|
JOE
|
13
|
M
|
weight
|
105
|
-Jeff