How to use a XPath expression based on a WebElement?

Hello!

I want to get a WebElement with a XPath expression based on another WebElement.

// With 'Table.getRowsOfATableByXPath(param)' I get all tag <tr> contained into param.List<WebElement> rows = CustomKeywords.'Table.getRowsOfATableByXPath'('//*[@id="dzA26"]/table')
    for(int row = 1; row < rows.size(); row++) {
         WebElement element = rows.get(row).findElement(By.xpath('/td[4]'))         println element.getText();
    }
}

The result expected is something like:

//*[@id="dzA26"]/table/tbody/tr[row]/td[4]

However this error occured

Test Cases/Filters/Search FAILED because (of) org.openqa.selenium.NoSuchElementException: no such element: Unable to locate element: {“method”:“xpath”,“selector”:"/td[4]"}

I hope my question is clear.

Thank’s a lot for your help!

**EDIT 1 **: Current solution

The current solution find is to use a second time the first XPath expression but I don’t like this solution…

List<WebElement> rows = CustomKeywords.'Table.getRowsOfATableByXPath'('//*[@id="dzA26"]/table')
    for(int row = 1; row < rows.size(); row++) {
         WebElement element = rows.get(row).findElement(By.xpath('//*[@id="dzA26"]/table/tbody/tr[' + row + ']/td[4]'))         println element.getText();
    }
}

Try changing ‘/td[4]’ to ‘//td[4]’

This solution seems to work!
But I don’t understand why, can you explain me please?