It how to achieve "Great" yet dangerous Wisdom.
When the "Murtaugh" from the other layers all where at the same place, which was the Kent Falls. they all put their arm into one of the Waterfall at the same time.When Murtaugh put his arm into the waterfall, he noticed that he no longer had an arm, but seven of them. That was not something unexpectable.
What is a miracle, though, is that after he removed his arm from the waterfall - he still could see all seven layers of his left arm.
Not longer after that he understood, that focusing them all in one place created a portal. That was because all of his arms from all of the layers met at one place and caused he interdimensional karma flow at his fingertips.
That picture, it shows how the "Murtaughs" can "Focus".