find multiple occurrences of a string within big string

[mancunian]

How do i search for multiple occurrences of a string within a string please and return the text next to it (big string is a copy of web page)

e.g.

Big string to search with 4 lines=

"value 1= blue
value 2 = red
value 1 = green
value 3= black"


1. Search for ALL occurrences of value 1

Result=

"value 1= blue
value 1 = green"

OR

2. Search for all occurrences of value 3

Result=

"value 3 = black"

Thank you in advance