great jo providing the setup data!

Here's another fast way using the PARSENAME function;

PARSENAME is usually used to split object names, like ServerName.Databasename.dbo.TableName,

but can be used for IP address and other strings, and is limited to 4 parts.

it also thinks the strings are right to left(4,3,2,1), where we would see the string as left to right (1,2,3,4)

note that this assumes your data will not have periods in it,

and is all three parts like your example data.

select

PARSENAME(REPLACE(SplitValue,'-','.'),3) AS PartT1,

PARSENAME(REPLACE(SplitValue,'-','.'),2) AS PartT2,

PARSENAME(REPLACE(SplitValue,'-','.'),1) AS PartT3,

MytestTable.*

FROM MytestTable