How does vue-router configure routes that do not have UI nesting relationships but require paths to be nested?

for example: the path is a router-view b, but there is no nesting relationship between an and b on pages that are completely independent, that is, a does not have < children > < / router-view >. Now the solution is not to use children nesting, the child and the parent level, and then the path of the child is written as

.

specify path as / a code > when configuring routes

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