Hello Manami
The answer is, it depends on the portchannel configuration. If you unconditionally create a portchannel on all of the interfaces involved using the channel-group 1 mode on command, the portchannel will look like it is functioning correctly between ESW2 and ESW3. The port between ESW3 and ESW1 will be observed as “stand-alone” in the output of the show etherchannel summary command, meaning that the link is isolated and cannot be integrated into the bundle.
If you use PAgP or LACP, you will find similar situations, where only the two links between switches 2 and 3 are active. The other link will simply not be used.
MLAG is multi-chassis link aggregation and is a generic term that refers to the creation of EtherChannel or port-channel links across multiple devices, much like in your diagram. Cisco has several ways in which this can be accomplished. One of these methods is to use what is known as a virtual port channel or vPC. Now this is a feature that is specific to the Cisco Nexus series of switches and is not available on IOS devices. However, there are solutions to implement MLAG on IOS devices, and these are described in the following post, with appropriate links:
I hope this has been helpful!
Laz