In the literature, it seems that for different set of 'h' & 'm' values, the break-points are different. Scatter plot / trend line doesn't seem to serve the case. Of course, it would be then 'pre-specified test'.
On Eviews you have several tests for break points. You can use BP using different hypothesis and after using the Chow test in the break points detected in BP. If the Chow test acept the break points of BP you can accept it. It is very important analysing if the break points correspond to a economic change (In EU is very important 1998-2000 because in that time we sign the EMU)