Voilą
If you didn't already do it, update to DOTween Pro's latest version, then overwrite the Demigiant/DOTween folder with the one attached here. After that, you can do:
myDOTweenPath.GetTween().PathGetDrawPoints();to get a series of points you can use to draw the path at runtime. Note that PathGetDrawPoints also accepts an optional parameter to tell it how many subdivisions per segment to create. The higher the subdivisions, the more points will be generated and the more curved it will look when drawn (in case of curved paths: it's completely ignored in case of linear ones). The default value, 10, should be already ok anyway.
Here is also an example MonoBehaviour that I used to test it:
using UnityEngine;
using System.Collections;
using DG.Tweening;
public class PathsWDrawPaths : MonoBehaviour
{
public DOTweenPath path;
public int subdivisionsXSegment = 10;
public Color startColor = Color.white;
public Color endColor = Color.white;
public float startW = 1;
public float endW = 1;
public Material material;
void Start()
{
Vector3[] drawPoints = path.GetTween().PathGetDrawPoints(subdivisionsXSegment);
int pointsCount = drawPoints.Length;
LineRenderer lr = path.gameObject.AddComponent<LineRenderer>();
lr.material = material;
lr.SetColors(startColor, endColor);
lr.SetWidth(startW, endW);
lr.SetVertexCount(pointsCount);
for (int i = 0; i < pointsCount; ++i) lr.SetPosition(i, drawPoints[i]);
}
}