Subway transfer point for one fare

I will be using an IC card ( Icoca) in the Osaka area. Hyperdia schedule requires a transfer to get to my destination. When I get to the transfer station, how do I take advantage of getting a through fare rather paying a point to point fare? Is there a different gate I need to use to transfer to the next subway line? Eg. Umeda (subway) to Ebisucho (osaka) via Dobutsuen-Mae.
Midosuji line to Sakaisuji line on the Osaka City Subway line.

in most cases, follow the signs that lead to the line you want to transfer to and there will be no gate to go thru.

When I get to my destination station, do I need to swipe my Icoca card again as I exit the gate? If so, will the card reader detect the through fare?

when you swipe your card at the destination it will calculate the fare based on the distance between the origin and destination using the shortest possible route.

@ Gayle
Depend on transfer station and railway company.
Osaka city subway 3 Umeda name station "Umeda[梅田]",
"Higashi-Umeda[東梅田]" and "Nishi-Umeda[西梅田]"
within 30 min transfer(re-enter) valid. http://urx.nu/dBEP

Umeda[梅田] - dobutsuenmae[動物園前] - Ebisu[恵比須] tranfer
is not need re-touching.
http://urx.nu/dBJa [stn map caputured with directions]
But choiced wrong route (up to [C] and gate out)
need re-touching and over paying as get off station
"Umeda to dobutsuenma" and "dobutsuenmae to Ebisu" fare.
So ask station staff or someone wrong gate out
or checked each rail company web before. [駅情報(stn info)][構内図(stn map)]

@.. (guest)
Not all detour route and stations.
Need to thru limited transfer stn gate and touching.