How vue.js positioning table frame xpath

In the past two days locate an element, I would like to locate a second viewing device.

 Both the information button labels are the same, so by this way Console: ($ x ( "xpath statement") This is the Google browser Debug Console syntax)

$x("//button[@class='el-button el-button--primary el-button--mini is-round']")

There are two search results

Later asked to develop, develop said it was written by vue.js framework, which is a table label, so they are the same. And found that indeed is the table label 

So we want to locate the second row to see the device on it, add a prefix. xpath follows 

$x("//tr[2]//button[@class='el-button el-button--primary el-button--mini is-round']")

The results are as follows:

 Positioning is successful, you can test it in robotfrmework inside.