Yes, those two will be identical.
While the string manipulation's in the select, that derived column is used in the where, so it's absolutely the same as having the string manipulation in the where.
Both of these, for example, are not SARGable and will simplify to the same query structure.
SELECT <columns> FROM SomeTable
WHERE Substring(SomeColumn,2,3) = 'abc'
SELECT * FROM (
SELECT <columns>, Substring(SomeColumn,2,3) as TrimmedString FROM SomeTable
) sub
WHERE sub.TrimmedString = 'abc'
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability