Printing Lines between two Two Pattern

You may use this awk:

awk '
/^Pattern1$/ {s = $0 ORS; next}
s != "" {s = s $0 ORS}
/^Pattern2$/ {printf "%s", s; s = ""}
' file

Pattern1
text7
text8
Pattern2
Pattern1
text15
text16
Pattern2
Pattern1
text7
text2
text8
Pattern2

$ awk '
/Pattern1/,/Pattern2/ {   # between the first start and end markers
    if(/Pattern1/)        # at the begin marker...
        b=$0              # ... reset buffer
    else 
        b=b ORS $0        # or keep on buffering
    if(/Pattern2/)        # at the end marker...
        print b           # ... it is time to output
}' file

head -4 of output:

Pattern1
text7
text8
Pattern2
...

Making a whole lot of assumptions about unstated requirements like whether to match to the first or last Pattern2, what to do if one or the other is missing from a file,what to do if both "patterns" occur on 1 line, etc.:

$ cat tst.awk
/Pattern1/ { f=1; rec="" }
f {
    rec = rec $0 ORS
    if ( /Pattern2/ ) {
        printf "%s", rec
        f = 0
    }
}

$ awk -f tst.awk file
Pattern1
text7
text8
Pattern2
Pattern1
text15
text16
Pattern2
Pattern1
text7
text2
text8
Pattern2

See also How do I find the text that matches a pattern?.

If you just want to do it in one gulp, you can use perl:

perl -0777 -nE 'say $1 while (/(^Pattern1$
        (?:\R(?!^Pattern2$|^Pattern1$).*)*\R
    ^Pattern2$)/gmx)' file
Pattern1
text7
text8
Pattern2
Pattern1
text15
text16
Pattern2
Pattern1
text7
text2
text8
Pattern2

This might work for you (GNU sed):

sed -n 'H;/Pattern1/h;/Pattern2/{g;p}' file

Turn off implicit printing by setting -n.

Append the current line to the hold space (spare buffer).

If the current line contains Pattern1, replace the hold space by this line.

If the current line contains Pattern2, replace the current line by contents of the hold space and print the result.