正しく理解できたかどうかわかりませんが、タイトルの下にティーザー テキストを表示しますか? jquery を使用して、パネル タイトルにテキストを追加してみませんか。
<div class="panel-group" id="accordion" role="tablist" aria-multiselectable="true">
<div class="panel panel-default">
<div class="panel-heading" role="tab" id="headingOne">
<h4 class="panel-title">
<a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
Collapsible Group Item #1
</a>
</h4>
</div>
<div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne">
<div class="panel-body">
1 Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et.
</div>
</div>
</div>
<div class="panel panel-default">
<div class="panel-heading" role="tab" id="headingTwo">
<h4 class="panel-title">
<a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
Collapsible Group Item #2
</a>
</h4>
</div>
<div id="collapseTwo" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingTwo">
<div class="panel-body">
2 Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et.
</div>
</div>
</div>
</div>
$(function(){
$("#accordion .panel").each(function(){
var thispanel = $(this);
var titletext = thispanel.find(".panel-body").text().substring(1, 100) + " ... click to read more";
thispanel.find("h4.panel-title a").html(titletext);
});
});