[Tex/LaTex] How to position one node below another so that shorter one starts where the wider one does (instead of being centered)

Question

I need bottom nodes to start where their respective top nodes instead of being centered below them.

Output:

Code:

\begin{tikzpicture}
\node[align=left,draw=black,rounded corners](colOne_rowOne)
{
this is line 1\\
this is line 2, this is line 2
};
\node[below=of colOne_rowOne,align=left,draw=black,rounded corners](colOne_rowTwo)
{
this is line
};
\node[right=of colOne_rowOne,align=left,draw=black,rounded corners](colTwo_rowOne)
{
this is line 1\\
this is line 2, this is line 2
};
\node[below=of colTwo_rowOne,align=left,draw=black,rounded corners](colTwo_rowTwo)
{
this is line
};
\end{tikzpicture}

Answer 1

While @Zarko's answer is working in this case, I think it is cleaner to use anchors for this:

\begin{tikzpicture}[box/.style={align=left,draw=black,rounded corners}]
    \node[box](colOne_rowOne)
    {
        this is line 1\\
        this is line 2, this is line 2
    };
    \node[box, below=of colOne_rowOne.south west, anchor=north west](colOne_rowTwo)
    {
        this is west-aligned
    };
    \node[box, right=of colOne_rowOne](colTwo_rowOne)
    {
        this is line 1\\
        this is line 2, this is line 2
    };
    \node[box, below=of colTwo_rowOne.south east, anchor=north east](colTwo_rowTwo)
    {
        this is east-aligned
    };
\end{tikzpicture}

Anchors are fitted for this task: they tell which point of the current node should be positioned at the given coordinate. Then you can use the node distance key to change the distances between the nodes.