Just as a father has mercy on his children, please Hashem, have mercyon us. (Etz Yosef) From this point on in the Birkas Hamozohn, weask Hashem for things which are similar to our prayers in the"Sh'mohneh Esray". "Rachaym" - (Have mercy),is like the tenth blessing in "Sh'mohneh Esray", whichis "T'ka B'shohfar" - (Sound the great shofar). Wedaven to Hashem that He should gather together all of those inexile. (Iyun T'filo) "v'al Y'rushola-yim irecho" - (Andon Jerusalem, Your city)
This can be compared to the fourteenth "brocha" of"Sh'mohneh Esray" which begins with the words,"v'liyrushola-yim irecho" - (and to Jerusalem Yourcity, return in mercy). (Iyun T'filo) Hashem says, "I willreturn to Zion and stay in Jerusalem." (Z'charyah 8:3)Jerusalem is the capital of Hashem's kingdom and the BaysHamikdosh was built there. (Radak)